ROME — A U.S. soldier went on trial in absentia Tuesday for the shooting death of an Italian intelligence agent at a checkpoint in Iraq two years ago, a case that strained relations between Rome and Washington.

The judge immediately adjourned the proceedings against Spc. Mario Lozano, 37, until May 14 for technical reasons.

The agent, Nicola Calipari, was shot March 4, 2005, on his way to the Baghdad airport shortly after securing the release of a kidnapped Italian journalist, Giuliana Sgrena. Sgrena and another agent who was driving the car were wounded.

Lozano was indicted in February on charges of murder and attempted murder.

Franco Coppi, who is representing Calipari’s widow, said Tuesday before the hearing opened at a high-security courtroom on Rome’s outskirts that Lozano’s absence was not a detriment to the proceedings.

“His absence is his own choice. It does not represent an obstacle to ascertaining the truth,” Coppi told reporters. “We are absolutely serene. The evidence gathered is indisputable.”

In recent comments to the U.S. media, Lozano defended his actions, saying he had no choice but to fire. He says he flashed a warning light signaling the vehicle to stop and that he shot first at the ground, and then at the car’s engine.

Reached by telephone late Monday in New York, Lozano told The Associated Press he could not comment ahead of the trial.

Fabrizio Cardinali, Lozano’s former court-appointed lawyer, told the AP ahead of the trial that the shooting was the result of the Italians’ “lack of caution.”

“What happened was not the fault of the checkpoint, but the fault of the Italians who did not have any military escort,” said Cardinali. Lozano’s current lawyer was not immediately available for comment.

Rome has not sought Lozano’s extradition, but the Pentagon has indicated that he would not be extradited anyway, saying it considered the incident a “closed matter.”

Sgrena, who attended Tuesday’s hearing, lamented Lozano’s absence as well as what she said was a lack of U.S. cooperation in the investigation, saying they both were “obstacles” to justice.

“I hope that we will have a piece of the truth,” she said.

Anger over deathThe death of Calipari, hailed as a hero in Italy, angered Italians, most of whom are opposed to the Iraq war.

It soured relations between Italy and the United States, with the two countries failing to reach shared conclusions and issuing separate reports on the incident.

U.S. authorities have said the vehicle was traveling fast, alarming soldiers who feared an insurgent attack. Italian officials claimed the car was traveling at normal speed and blamed the U.S. military for failing to signal there was a checkpoint. It also contended that stress, inexperience and fatigue played a role.

In a separate case, also an irritant to bilateral relations, Italian prosecutors have indicted 26 Americans, all but one believed to be CIA agents, accused of kidnapping an Egyptian terror suspect in Milan as part of the CIA’s extraordinary rendition program.